1. Field of the Invention
The invention relates to writing instruments which are ergonomically adapted to a user's hand posture. The term “writing instruments” is understood to comprise all writing instruments which are adapted to be handled and transported, i.e. which are used by a user as a ball-point pen, roller ball, felt pen or fountain pen. Writing instruments with ink devices or refill cartridges are also comprised.
2. Prior Art
Many decades ago, efforts were made to provide the tip shape of a writing instrument at the front end of a shaft with a shape tapered towards the front end and to simultaneously incline the tip in relation to the axis of the writing shaft, compare the old documents FR 1,032,122 A (Segal/Flicker), FR 2,151,240 A (Droubay) or the old German document DE 871 258 C (Riepe-Werk).
Only in recent years, the concept has been taken up again to improve the idea of an inclined writing tip with regard to industrial engineering, said obviously outdated idea having disappeared from the catalogue of ideas of the manufacturers of writing instruments, see for example documents WO 98/13216 A1 (Senator/Vial) or WO 97/22482 A1 (Gilette). Whereas the last mentioned WO-document relates to a tip design as described in the first mentioned FR-document, namely designing the front end as a double curvature of a tip device tapered towards the front to obtain an orientation directed away from the writing surface on one hand, and on the other hand, very close to said tip device, an orientation directed towards said writing surface again, the last but one WO-document by Vial proposed to provide a writing tip inclined in one direction only, an elongated design of a front end being selected as an inclined or “asymmetrical” cone at the front shaft end. Such a design permits to improve the control by the user who has a better view of the writing end of the writing instrument due to the slim elongated tip.
The modernization in the field of technical engineering according to the preceding paragraph concerned a stationary tip inclination. Already many years ago, an adjustable tip arrangement according to DE 801,614 (dating 1951, Ganter) was proposed in which a ball or disk joint relative to a schematically indicated tip was provided, said tip having been mounted at a shaft with a nut (designated d there) after adjusting said ball-disc joint. Still earlier, in 1928, a writing instrument was proposed in U.S. Pat. No. 1,687,647 (Garvey), said writing instrument permitting a very closely limited tip inclination, oriented at an axially arranged “rigid tip holder 10” as described therein and releasing the flow of a writing medium upon being slightly bent. Upon bending, the user adjusts the rate of flow of the writing medium to generate thick and thin lines by correspondingly pressing on the tip (compare page 2, lines 38 to 52 of said document). Finally in 1971, it was proposed to provide a tube arrangement with a disc joint at the front end and with a tip, said tip being adapted pivotable relative to an axis of said tube, compare U.S. Pat. No. 3,554,660 (Wood). According to this document, a disc-shaped joint (designated 9,10 in FIG. 2 of said document) is axially offset and laterally offset with respect to a pivoting plane (3—3 therein).